The head of the upper arm bone fits into a shallow socket in your shoulder blade. Strong connective tissue, called the shoulder capsule, surrounds the joint.

To help your shoulder move more easily, synovial fluid lubricates the shoulder capsule and the joint.

In frozen shoulder, the shoulder capsule thickens and becomes tight. Stiff bands of tissue — called adhesions — develop. In many cases, there is less synovial fluid in the joint.”(3)

Frozen shoulder typically occurs in three stages:

Freezing, or painful stage: The pain gets progressively stronger and the shoulder becomes stiff. Movements worsen pain and become harder and harder to accomplish. Also, the pain may worsen at night. This stage lasts 6-9 months.

Frozen (adhesive) stage: Pain either stays constant or improves. The shoulder gets increasingly stiff and its range of motion is severely limited, making daily life difficult. This stage lasts 4-6 months.

Thawing stage: Movement of the shoulder begins to improve and pain fades. It may occasionally return during and after healing. At the end of this 6-month stage, strength and motion should return to normal, although it can take up to 2 years for a full recovery.